If not the tools it the madmen that the problem see below and there are over 200 millions firearms in the US so good luck in limiting access or waving a magic wand to get rid of them so we can go on to licensing large knives.
http://www.cnn.com/2012/12/14/world/asia/china-knife-attack/index.html
Beijing (CNN) -- Twenty-two primary school children were wounded in a knife attack Friday in central China, authorities said.
The attack took place at the entrance to the Chenpeng Village Primary School in Henan province, according to the public information department of Guangshan county, the area where the school is located. An adult was also wounded, it said.
Several of the children are in critical condition, the state-run website Chinanews.com said, citing local authorities.
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Police say they have detained a suspect, a 36-year-old man from the village, state media reported.
Initial assessments suggest the man is mentally ill, Chinanews.com said, citing Guangshan authorities.
China was hit by a spate of knife and cleaver attacks that targeted school children in 2010.
A number of measures were introduced at the time, including increased security at schools across the country and a regulation requiring people to register with their national ID cards when buying large knives.
